Telephony.



' 0. A. BALS.

TELEPHONY.

APPLICATION TILED MAY 22,1011.

Patented 0t.8,1912.

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G. A. BALS.

TELEPHONY.

APPLICATION FILED MAY 22,1911.

1,040,635. Patented 0ct.8,1912.

2 SHBETS-SHBBT 2.

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STAS ATENT OFFICD CHARLES A. BALS, OF CHICAGO, ILLINOIS, ASSIGNOR T0CORW'IN TELEPHONE MANUFACTURING COMPANY, A CORPORATION OF ILLINOIS.

TELEPHONY.

Specification of Letters Patent.

PatcntedOct.8,1912.

Application filed May 22, 1911. Serial No. 628,749.

To all whom it may concern:

Be it known that 1, CHARLES A. Bans, citizen of the United Statesresiding at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Telephony, of which thefollowing is a full, clear concise, and exact description, referencebeing had to the accompanying drznvings, forming a part of thisspecification,

My invention relates to that class of telephone exchange systems inwhich telephone lines are automatically extended at the ex change and myinvention broadly contour plates such a telephone exchange systemwhether the extensions terminate at called telephone stations or aremore links between calling and called telephone lines.

My invention relates particularly to the switching mechanism that isemployed at the telephone stations for operating theselecting mechanismat the exchange for automatically extending telephone lines.

My invention has for its object the provision of a construction wherebythe operating portion of the switcl'iing mechanism may be formed in anindividual unit, said unit being separably associated with the cir cuitthat it to control. The (merating unit of the switching mechanism isprovided with terminals for separably including the switchingniechanisn'i in the circuit that it is to control, these terminalshaving cow tacts that are mouutml imliuieudently ot' the aforesaidterminals whereby the switching mechanism including these latterterminals may be removed without disturbing the connections of thecircuit conductors leading to said contacts.

In the preferred en'il'iodiment ol' the invention the terminals arc'inthe form of leaf springs which are carried by the Li'ramcwork thatsupports the switching mechanism. The contacts are desirably in the Formof screws against which the spring terminals are pressed when theswitching mechanism is put in position, these contacts being mountedupon a framework or casing upon which the switching mechanism isremovably secured.

I will explain my invention more fully by reference to the accompanyingdrawings showing the preferred einbodin'ient thereof as employed inconnection with a subscribcrs desk stand that enters into a common Inthe drawings Figure 1 is a side clevation of a desk stand equipped inaccordance with the preferred embodiment of the invention; Fig. 2 is afront elevation of the structure shown in Fig. 1; Fig. 3 is a view inelevation showing the apparatus of my invention, the lower portion ofthe desk stand casing, framework, or mounting that carries thisapparatus being shown in sec: tion; Fig. i is a bottom view of thestructure shown in Fig. 3: Fig. is a diagrammatic view showing thecircuit connections that are effected by the equipment il1ustrated inthe other figures.

Like parts are indicated by similar characters oi reference throughoutall of the views.

The side 1 of a telephone line is connected with a contact screw that iscarried upon a mounting plate 3, this mounting plate bcl'ng desirablyrcmovably secured to a main mounting 4 that, in the embodiment. of theinvention illustrated, is cimstituted of the base ot' the desk stand.There is an inner basclike structure 5 that is removably secured to thedesk stand by an upward extension 6 screwed to the cylindrical portion 7of the desk stand by fastening screws 8, though other means may beemployed for uniting the inner base 5 with the stem 7 of the desk standand with the main mounting 1 through the intermcdiaiion of said stem.The mounting plate 3 is rcmovably secured to the element 5 by means oispring clips 8. The other side S) of the tclcplume line isdiagranunatically illustrated in liig. 5 as being connector l with thetelephone receiver switch book 10, the normal contact of this switchhook constituting one terminal of the bridge coudu .:tor whose otherterminal is permanently connected with the side 1 -o[ the line and whichbridge conductor includes a signal receiver 11 and a condenser 12. Thealternate contact 13 ot' the switch hook is connected with a screwcontact 1 1 similar in mechanical construction to the screw contact 2and similarly mounted upon the mounting plate 53. The alternate contact15 of the switch hook is connected thrtmgli the telephone receiver 10and the telephone transmitter 17 with a contact screw 18 simi-' lar inmechanical construction to the contacts t2 and 14 and similarly mountedin lie the mounting plate 3.

Theswitching mechanismior modifying the line circuit in order to set theselecting mechanism at the exchange into operation includes springcontacts 19, 20, and 21 that are adapted for engagement with the screwcontacts 2, 14 and 18 respectively. The

spring contact 19 is connected with a CiI' cuit opening. andclosingspring 22 provided with; a contact 23 that itnormally engages and,which contact 23 is connected with the spring contact 21.

mechanism which is employed at the substation for operating theselecting mechanism is idle, circuit between the line sides 1 and 9' iscompleted throughthe telephone receiver 16, when this receiver isremoved from its switch hook, by way of a bridge connection which may betraced from the side 1 through the screw contact 2, the spring contact19, tli e' circuit opening and closing contacts 22 and 23, the springcontact 21,

the screw contact 18, the transmitter 17, the 251 receiver 16,thmterminal contact of the, receiver that is then engaged with theswitch hook 10, said switch hook'lO to the side 9. When the selectingmechanism is to be operated, thebridge conductor between the sides ofthe telephone line is interrupted at 22, 23, it being usual to shunt outthe receiver and transmitter when circuit interruption occurs at 22 23to avoid objectionable noise in the telephone receiver 16.. This resultis accomplished by providing the additional elements 13, 14 and whichhave been described and also the normally open shunt switch contacts 24and 25, these latter contacts being-closed during the circuitinterrupting operation by mechanism which 18 well understood, the shuntabout the receiver and transmitter then established being traceablefromthe contact 21, through the contacts 24' and 25 that are engagedduring the dialingoperation. the contacts 14 an]. 20, the contact 13 tothe switch hook 10. The element which is employed for bringing contacts24 and 25' together is diagrammatically illustrated at 26 but inasmuchas the mechanism by which this element 26 is operated is so well known Iwill not describe its operation. The mechanism that interrupts thebridge conductor at 22 and 23 includes a cam 2'? that engages thecontact,23 to move it from its companion 22 to cpeh the bridge conductorand to permit thecontact 23, by its own resilience, to move toward thecontact 22 to engage 1t and thereby c'lose the bridge conductor. Thiscam is operated by means of dial mechanism 28 which is so very wellunderstood as to render a description thereof superfluous. The dialmechan ism" 28, the com 2?, the spring contacts 19,20 and 21, the bridgemaking andbreaking contacts 22 and 23, the telephore When thatswitching.

noaaesa receiver and transmitter shunting contacts 24 and 25, and theelement 26 that establishes the shunt connection at 24 and 25 whendialing is taking place areall provided upon a framework or mountingthat includesa bottom plate 29, a top plate 30 and posts or struts 31thatlconstitute distance preserving devices for, maintaining the plates29 and 30 in proper relation. These posts 31 also 1 serve as anchorage'means whereby the base 4 and the mounting for the parts 19' to 26inclusive which have just been'described may be separably secured'together. I prefer separably 'to secure the base 4 and the mounting forthe parts 19 to 26 inclusive in position by means of screws 32 that passthrough the cylindric 1 projection 33 of the base 4 andinto the po tsBl.

The line sides 1 and 9 of the telephone line may be associated with thecontacts 2,

14 and 18 in a way that is mechanically in-= dependent of the wiringthat associates the part-s19 to 25 inclusive, these latter parts beingelectrically associated and mechanically supported by amounting that isstructurall'y distinct from the mounting 4 that carries the contacts 2,14 and 18, these two mountings being separably united in a manner topermit of the proper electrical asso ciation of the contacts carriedthereby when the.equipment is assembled.

The switching mechanism that is carried by the mounting structure thatis mainly imposed of the parts 29, 30 and 31 is, in

the embodiment of the invention illustrated, controlled by the dialmechanism that so commonly enters into the equipment that is carried byseparably engaged mountings; the

switchingmechanism being carried by one of said mountings; and amounting plate for the contact carried by the other mounting separablysecured to said other mounting a contact carried by the-mountingplatehav- .ing a lme conductor connected therewith which is bodily movablewith the contact and the-mounting plate for the contact.

2. Apparatus for automatically eifect-ing extension of telephone lineswhich includes switching mechanismfor governing the circuitoi": theselecting mechanism. that is to effect the line extension; engagingcontacts for establishing the circuit relation ,of said switchingmechanism and one of which is a spring contact, these contacts beingcarried by separably engaged m0untings,- the switching mechanism beingcarried by one of said mountings; and a mounting plate for the contactcarried by the other mounting separably secured to said other mounting acon- 10 tact carried bythe mounting plate having a my name thissixteenth day of May A. D., 15

CHARLES A. BALS. Witnesses G, L. Came, E. L. WHITE.

